linux/drivers/iio/orientation/hid-sensor-rotation.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * HID Sensors Driver
 * Copyright (c) 2014, Intel Corporation.
 */

#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/hid-sensor-hub.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include "../common/hid-sensors/hid-sensor-trigger.h"

struct dev_rot_state {
	struct hid_sensor_hub_callbacks callbacks;
	struct hid_sensor_common common_attributes;
	struct hid_sensor_hub_attribute_info quaternion;
	struct {
		IIO_DECLARE_QUATERNION(s32, sampled_vals);
		/*
		 * ABI regression avoidance: There are two copies of the same
		 * timestamp in case of userspace depending on broken alignment
		 * from older kernels.
		 */
		aligned_s64 timestamp[2];
	} scan;
	int scale_pre_decml;
	int scale_post_decml;
	int scale_precision;
	int value_offset;
	s64 timestamp;
};

static const u32 rotation_sensitivity_addresses[] = {
	HID_USAGE_SENSOR_DATA_ORIENTATION,
	HID_USAGE_SENSOR_ORIENT_QUATERNION,
};

enum {
	DEV_ROT_SCAN_TYPE_16BIT,
	DEV_ROT_SCAN_TYPE_32BIT,
};

static const struct iio_scan_type dev_rot_scan_types[] = {
	[DEV_ROT_SCAN_TYPE_16BIT] = {
		.sign = 's',
		.realbits = 16,
		/* Storage bits has to stay 32 to not break userspace. */
		.storagebits = 32,
		.repeat = 4,
	},
	[DEV_ROT_SCAN_TYPE_32BIT] = {
		.sign = 's',
		.realbits = 32,
		.storagebits = 32,
		.repeat = 4,
	},
};

/* Channel definitions */
static const struct iio_chan_spec dev_rot_channels[] = {
	{
		.type = IIO_ROT,
		.modified = 1,
		.channel2 = IIO_MOD_QUATERNION,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
					BIT(IIO_CHAN_INFO_OFFSET) |
					BIT(IIO_CHAN_INFO_SCALE) |
					BIT(IIO_CHAN_INFO_HYSTERESIS),
		.scan_index = 0,
		.has_ext_scan_type = 1,
		.ext_scan_type = dev_rot_scan_types,
		.num_ext_scan_type = ARRAY_SIZE(dev_rot_scan_types),
	},
	IIO_CHAN_SOFT_TIMESTAMP(1)
};

/* Channel read_raw handler */
static int dev_rot_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int size, int *vals, int *val_len,
				long mask)
{
	struct dev_rot_state *rot_state = iio_priv(indio_dev);
	struct hid_sensor_hub_device *hsdev = rot_state->common_attributes.hsdev;
	struct hid_sensor_hub_attribute_info *info = &rot_state->quaternion;
	u32 usage_id = HID_USAGE_SENSOR_ORIENT_QUATERNION;
	union {
		s16 val16[4];
		s32 val32[4];
	} raw_buf;
	int ret_type;
	int i;

	vals[0] = 0;
	vals[1] = 0;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (size >= 4) {
			if (info->size <= 0 || info->size > sizeof(raw_buf))
				return -EINVAL;

			hid_sensor_power_state(&rot_state->common_attributes, true);

			ret_type = sensor_hub_input_attr_read_values(hsdev,
								     hsdev->usage,
								     usage_id,
								     info->report_id,
								     SENSOR_HUB_SYNC,
								     info->size,
								     (u8 *)&raw_buf);

			hid_sensor_power_state(&rot_state->common_attributes, false);

			if (ret_type < 0)
				return ret_type;

			switch (info->size) {
			case sizeof(raw_buf.val16):
				for (i = 0; i < ARRAY_SIZE(raw_buf.val16); i++)
					vals[i] = raw_buf.val16[i];
				break;
			case sizeof(raw_buf.val32):
				for (i = 0; i < ARRAY_SIZE(raw_buf.val32); i++)
					vals[i] = raw_buf.val32[i];
				break;
			default:
				return -EINVAL;
			}

			ret_type = IIO_VAL_INT_MULTIPLE;
			*val_len =  4;
		} else
			ret_type = -EINVAL;
		break;
	case IIO_CHAN_INFO_SCALE:
		vals[0] = rot_state->scale_pre_decml;
		vals[1] = rot_state->scale_post_decml;
		return rot_state->scale_precision;

	case IIO_CHAN_INFO_OFFSET:
		*vals = rot_state->value_offset;
		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SAMP_FREQ:
		ret_type = hid_sensor_read_samp_freq_value(
			&rot_state->common_attributes, &vals[0], &vals[1]);
		break;
	case IIO_CHAN_INFO_HYSTERESIS:
		ret_type = hid_sensor_read_raw_hyst_value(
			&rot_state->common_attributes, &vals[0], &vals[1]);
		break;
	default:
		ret_type = -EINVAL;
		break;
	}

	return ret_type;
}

/* Channel write_raw handler */
static int dev_rot_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan,
			       int val,
			       int val2,
			       long mask)
{
	struct dev_rot_state *rot_state = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		ret = hid_sensor_write_samp_freq_value(
				&rot_state->common_attributes, val, val2);
		break;
	case IIO_CHAN_INFO_HYSTERESIS:
		ret = hid_sensor_write_raw_hyst_value(
				&rot_state->common_attributes, val, val2);
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}

static int dev_rot_get_current_scan_type(const struct iio_dev *indio_dev,
					 const struct iio_chan_spec *chan)
{
	struct dev_rot_state *rot_state = iio_priv(indio_dev);

	switch (rot_state->quaternion.size / 4) {
	case sizeof(s16):
		return DEV_ROT_SCAN_TYPE_16BIT;
	case sizeof(s32):
		return DEV_ROT_SCAN_TYPE_32BIT;
	default:
		return -EINVAL;
	}
}

static const struct iio_info dev_rot_info = {
	.read_raw_multi = &dev_rot_read_raw,
	.write_raw = &dev_rot_write_raw,
	.get_current_scan_type = &dev_rot_get_current_scan_type,
};

/* Callback handler to send event after all samples are received and captured */
static int dev_rot_proc_event(struct hid_sensor_hub_device *hsdev,
				unsigned usage_id,
				void *priv)
{
	struct iio_dev *indio_dev = platform_get_drvdata(priv);
	struct dev_rot_state *rot_state = iio_priv(indio_dev);

	dev_dbg(&indio_dev->dev, "dev_rot_proc_event\n");
	if (atomic_read(&rot_state->common_attributes.data_ready)) {
		if (!rot_state->timestamp)
			rot_state->timestamp = iio_get_time_ns(indio_dev);

		/*
		 * ABI regression avoidance: IIO previously had an incorrect
		 * implementation of iio_push_to_buffers_with_timestamp() that
		 * put the timestamp in the last 8 bytes of the buffer, which
		 * was incorrect according to the IIO ABI. To avoid breaking
		 * userspace that may be depending on this broken behavior, we
		 * put the timestamp in both the correct place [0] and the old
		 * incorrect place [1].
		 */
		rot_state->scan.timestamp[0] = rot_state->timestamp;
		rot_state->scan.timestamp[1] = rot_state->timestamp;

		iio_push_to_buffers(indio_dev, &rot_state->scan);

		rot_state->timestamp = 0;
	}

	return 0;
}

/* Capture samples in local storage */
static int dev_rot_capture_sample(struct hid_sensor_hub_device *hsdev,
				unsigned usage_id,
				size_t raw_len, char *raw_data,
				void *priv)
{
	struct iio_dev *indio_dev = platform_get_drvdata(priv);
	struct dev_rot_state *rot_state = iio_priv(indio_dev);

	if (usage_id == HID_USAGE_SENSOR_ORIENT_QUATERNION) {
		if (raw_len / 4 == sizeof(s16)) {
			rot_state->scan.sampled_vals[0] = ((s16 *)raw_data)[0];
			rot_state->scan.sampled_vals[1] = ((s16 *)raw_data)[1];
			rot_state->scan.sampled_vals[2] = ((s16 *)raw_data)[2];
			rot_state->scan.sampled_vals[3] = ((s16 *)raw_data)[3];
		} else {
			memcpy(&rot_state->scan.sampled_vals, raw_data,
			       sizeof(rot_state->scan.sampled_vals));
		}

		dev_dbg(&indio_dev->dev, "Recd Quat len:%zu::%zu\n", raw_len,
			sizeof(rot_state->scan.sampled_vals));
	} else if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
		rot_state->timestamp = hid_sensor_convert_timestamp(&rot_state->common_attributes,
								    *(s64 *)raw_data);
	}

	return 0;
}

/* Parse report which is specific to an usage id*/
static int dev_rot_parse_report(struct platform_device *pdev,
				struct hid_sensor_hub_device *hsdev,
				unsigned usage_id,
				struct dev_rot_state *st)
{
	int ret;

	ret = sensor_hub_input_get_attribute_info(hsdev,
				HID_INPUT_REPORT,
				usage_id,
				HID_USAGE_SENSOR_ORIENT_QUATERNION,
				&st->quaternion);
	if (ret)
		return ret;

	dev_dbg(&pdev->dev, "dev_rot %x:%x\n", st->quaternion.index,
		st->quaternion.report_id);

	dev_dbg(&pdev->dev, "dev_rot: attrib size %d\n",
				st->quaternion.size);

	st->scale_precision = hid_sensor_format_scale(
				hsdev->usage,
				&st->quaternion,
				&st->scale_pre_decml, &st->scale_post_decml);

	return 0;
}

/* Function to initialize the processing for usage id */
static int hid_dev_rot_probe(struct platform_device *pdev)
{
	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
	int ret;
	char *name;
	struct iio_dev *indio_dev;
	struct dev_rot_state *rot_state;

	indio_dev = devm_iio_device_alloc(&pdev->dev,
					  sizeof(struct dev_rot_state));
	if (indio_dev == NULL)
		return -ENOMEM;

	platform_set_drvdata(pdev, indio_dev);

	rot_state = iio_priv(indio_dev);
	rot_state->common_attributes.hsdev = hsdev;
	rot_state->common_attributes.pdev = pdev;

	switch (hsdev->usage) {
	case HID_USAGE_SENSOR_DEVICE_ORIENTATION:
		name = "dev_rotation";
		break;
	case HID_USAGE_SENSOR_RELATIVE_ORIENTATION:
		name = "relative_orientation";
		break;
	case HID_USAGE_SENSOR_GEOMAGNETIC_ORIENTATION:
		name = "geomagnetic_orientation";
		break;
	default:
		return -EINVAL;
	}

	ret = hid_sensor_parse_common_attributes(hsdev,
						 hsdev->usage,
						 &rot_state->common_attributes,
						 rotation_sensitivity_addresses,
						 ARRAY_SIZE(rotation_sensitivity_addresses));
	if (ret) {
		dev_err(&pdev->dev, "failed to setup common attributes\n");
		return ret;
	}

	ret = dev_rot_parse_report(pdev, hsdev, hsdev->usage, rot_state);
	if (ret) {
		dev_err(&pdev->dev, "failed to setup attributes\n");
		return ret;
	}

	indio_dev->channels = dev_rot_channels;
	indio_dev->num_channels = ARRAY_SIZE(dev_rot_channels);
	indio_dev->info = &dev_rot_info;
	indio_dev->name = name;
	indio_dev->modes = INDIO_DIRECT_MODE;

	atomic_set(&rot_state->common_attributes.data_ready, 0);

	ret = hid_sensor_setup_trigger(indio_dev, name,
					&rot_state->common_attributes);
	if (ret) {
		dev_err(&pdev->dev, "trigger setup failed\n");
		return ret;
	}

	ret = iio_device_register(indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "device register failed\n");
		goto error_remove_trigger;
	}

	rot_state->callbacks.send_event = dev_rot_proc_event;
	rot_state->callbacks.capture_sample = dev_rot_capture_sample;
	rot_state->callbacks.pdev = pdev;
	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
					&rot_state->callbacks);
	if (ret) {
		dev_err(&pdev->dev, "callback reg failed\n");
		goto error_iio_unreg;
	}

	return 0;

error_iio_unreg:
	iio_device_unregister(indio_dev);
error_remove_trigger:
	hid_sensor_remove_trigger(indio_dev, &rot_state->common_attributes);
	return ret;
}

/* Function to deinitialize the processing for usage id */
static void hid_dev_rot_remove(struct platform_device *pdev)
{
	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct dev_rot_state *rot_state = iio_priv(indio_dev);

	sensor_hub_remove_callback(hsdev, hsdev->usage);
	iio_device_unregister(indio_dev);
	hid_sensor_remove_trigger(indio_dev, &rot_state->common_attributes);
}

static const struct platform_device_id hid_dev_rot_ids[] = {
	{
		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
		.name = "HID-SENSOR-20008a",
	},
	{
		/* Relative orientation(AG) sensor */
		.name = "HID-SENSOR-20008e",
	},
	{
		/* Geomagnetic orientation(AM) sensor */
		.name = "HID-SENSOR-2000c1",
	},
	{ }
};
MODULE_DEVICE_TABLE(platform, hid_dev_rot_ids);

static struct platform_driver hid_dev_rot_platform_driver = {
	.id_table = hid_dev_rot_ids,
	.driver = {
		.name	= KBUILD_MODNAME,
		.pm     = &hid_sensor_pm_ops,
	},
	.probe		= hid_dev_rot_probe,
	.remove		= hid_dev_rot_remove,
};
module_platform_driver(hid_dev_rot_platform_driver);

MODULE_DESCRIPTION("HID Sensor Device Rotation");
MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("IIO_HID");